FIELD OF THE INVENTION
The invention relates to a closure part with a sleeve which is constructed for receiving an optical coupling socket and snugly enclosing an outer surface of the socket.
Suitable closure parts are used for reliably closing the receiving sockets for optical waveguides on electrooptical modules from the production process up until when the module is put into operation. In such cases, the closure parts are intended to seal the receiving sockets against dirt and water and retain a reliable and defined functional position. In addition, self-contamination of the receiving socket caused by the wearing of the closure part should be ruled out and the running off of liquid during testing for major leaks and cleaning of the module should be made possible.
A protective connector for closing an electrooptical module is described in U.S. Pat. No. 5,243,678. Attached to a grip is a covering flange, which carries at least one parallel alignment pylon. The end surface of the alignment pylon is adapted to depressions of an optically active component. The alignment pylon is surrounded by a collar, which is attached to the covering flange and carries pressing webs on its outer side. The alignment pylon completely penetrates a receiving socket of the electrooptical module in an inserted state. A receptacle of the module in which the receiving socket is located then encloses the collar of the protective connector, with the protective connector being fixed in the receptacle by the pressing webs. The covering flange completely seals the receptacle at the end surface. The alignment pylon projects out of the back end of the receiving socket and aligns an optically active component with its end surface. That provisional alignment takes place in order to be able to fasten the optically active component permanently in the module in an aligned manner. Furthermore, the protective connector is intended to protect the optically active component and the receiving socket against contamination. However, the protective connector cannot prevent self-contamination, since it passes through the receiving socket up to the optically active component. Similarly, protection against water is only inadequately ensured.
A protective cap for optical waveguide plug-in connections is described in Published European Patent Application 0 312 147A2. The protective cap offers connecting surfaces, for a coupling part and a connector, on both sides of an intermediate body. In that case, the connecting surfaces are provided axially opposite one another and make it possible for the coupling part and the connector to be received simultaneously. The protective cap essentially only prevents the depositing of dust on the sensitive end surface of the optical waveguide in the connector or in the coupling. The protective cap is not watertight.
A closure part of the type stated at the outset above is described in U.S. Pat. No. 4,640,575 in the form of a protective cap for a socket for receiving optical waveguides. The socket is fastened on a base plate. The protective cap, which is resiliently mounted, is likewise attached to the base plate at the side of the socket. Whenever the socket is not connected to a connector, the protective cap, which is formed of an elastic material, covers the socket, acting as a shroud around it on the outside against dust. If an optical waveguide connector is removed from the socket, the protective cap snaps over the socket and covers it. The protective cap can be pressed firmly onto the socket by additional axial force. The protective cap is unsuitable for electrooptical modules with receptacles and does not guarantee adequate protection against moisture.